Apparatus for and method of sealing bags



Aug. 16, 1938. s. MOORE 2,126,908

APPARATUS FOR AND METHOD OF SEALING BAGS 2 Sheets-Sheet 1 Filed June 12, 1935 4 f @,//4 II- E- E i 44 INVENTOR.

/57 EZQQTZlZYOOT 20M BY ATTORNEYJ Aug. 16, 1938. s. MOORE 2,126,908

APPARATUS FOR AND METHOD OF SEALING BAGS Filed June 12, 1935 2 Sheets-Sheet 2 ATTORNEY Patented Aug. 16, 1938 1 UNITED STATES PATENT ()FFICE 2,126,908 APPARATUS FOR ANIAgIETHOD OF. SEALING B S Stuart Moore, Dallas, Tex., assignor to Dixie Wax Paper Company, Dallas, Tex., a corporation of Texas Application June 12, 1935, Serial No. 26,255

Claims. (Cl. 154-42) My invention relates to machines for making ing description based thereupon, set out an emwaxed, paraflined or the like coated paper bags, bodiment of the same.

from paper which has been treated with a sub- In the drawings, wherein like characters of stance which makes it adhesive repellent. reference designate corresponding parts through- More particularly, my invention provides imout: 5 proved means for applying heat to the longitu- Fig. l is a side elevation showing diagrammatb dinal seam of the web of coated paper subsequent cally my bag sealing apparatus as applied to a to its folding to form overlapping edges constibag making machine. tilting-said scam, in order to effectively seal said Fig. 2 is a plan view of Fig. 1, showing the seam. course of the formed overlapping edges of the it) My inventipn provides a travelling or movable web past the sealing apparatus. heating element adapted to move in contact with Fig. 3 is an edge view of the sealing disc and said overlapping edges, and to apply heat theresupporting and current supplying parts. to, comprising an electrical heater element which Fig. 4 is a face view of the sealing disc with is easily removable. Darts removed, showing the spiral electrical heatis An object of my invention is to provide means ing element, the plate for retaining the-heating for eifectively and tightly sealing the seams of element, and the current leads.

paper bags made from waxed or similarly treated Fig. 5 is a cross-sectional view of the sealing papers in order that such bags may withstand disc taken on the line 5-5 of Fig. 4. considerable pressure from the contents. Fig. 6 is a detail view of the assembled sealing 20 A further object of my invention is to provide disc and heating element and supporting and a movable heated sealing member to move in current supplying parts. contact with the overlapping edges to be sealed Fig. 7 is a sectional view of the several parts of at substantially the same rate of speed as said the sealing disc with the parts separated in overlapping edges, or at a slightly slower speed. juxtaposition, showing the electrical heater ele- 25 A still further object of my invention is to proment and its retaining plate. vide a device which is capable of being readily In Fig. l, I represents the bed of a commonly and easily installed upon or removed from an used bag making machine, over which passes the ordinary bag making machine according to the formed paper web after it has been folded 30 type of paper being used, without necessitating over to form the longitudinal'seam of the bags 30 material changes therein, so that the installato be manufactured from separateedge folds of tion of the particular construction embodying the paper 3| and 32. At each side of the bed I my present invention will notinvolve any unwaris provided a pair of oppositely positioned bearing 1 ranted expense and labor. supports 2, each carrying a bearing member 3.

Another object of my invention is to provide a The bearing members 3 are mounted in their sealing apparatus wherein the movable heat-aprespective supports 2 for variable adjustment by plying sealing member makes only a brief conmeans of a set bolt 4 which may be completely tact with the moving paper web, thus offering disengaged from the bearing members to permit little or practically no resistance to the movethe removal of the latter when desired.

40 ment of the latter, thereby accelerating the rate A pair of feed rolls are positioned intermediate 40 of production. the bearing supports 2, comprising the upper feed A still further object of my invention is to roll 5 and the lower feed roll 6. The upper feed provide a movable heating element so mounted roll 5 is mounted on a shaft 8 which is carried on that said heating element with its associated the bearing members 3. One end of the shaft 8 parts will be rigidly or bodily mounted as a unit projects beyond a bearing member 3, and carries 45 with the web feed roll, whereby the heating eleon its extended portion a sprocket wheel I. ment will follow any displacements of the feed Rigidly fixed to the normal forward portion roll in order that both may be displaceable as a of the bearing 3 and mounted above the bed I u it, of the machine in substantial parallel relation Other objects of my invention will be in part to the feed roll 5, is a bar 9 to which is secured so obvious and in part pointed out hereinafter. by means of bolts Ill or the like, an arm II ar- In order that the invention and its mode of ranged at substantially right angles to bar 9 operation may be readily understood by persons and positioned in longitudinal direction with reskilled in the art, I have in the accompanying spect to the bed I of the machine. Preferably,

55. illustrative drawings and in the detailed followthe free extremity of arm II is bent downwardly as shown at l2, to carry a bearing bracket l3. This bearing bracket I3 is provided with a slot I through, which passes a lock bolt I5 for fixedly connecting the bracket 13 to the bent portion I2 of the arm Ii. The slot l4 provides convenient means for adjusting bracket ill in a vertical direction on its supporting arm H. A washer it may be interposed between the head of the bolt l5 and the adjacent portion of the bracket l3 to effect a more secure frictional engagement of the parts connected thereby. The bracket member l3 comprises a cylindrical bore adapted to constitute a bearing or journal 42 for journalling a stub shaft H.

The stub shaft I'I projects from both sides of bracket member I3, and is substantially parallel to feed roll shaft 8. To one end of stub shaft i1 is securely attached, preferably by keying, a sprocket wheel l8. Sprocket chain l9 connects sprocket wheel IS with the sprocket wheel 1 carried on feed roll shaft 8.

A movable heater element, here shown preferably as a metallic disc, 20, is keyed or fixedly carried on the other end of the stub shaft IT and is rotatable with shaft IT, The disc is mounted with its plane in the direction of travel of formed paper web between the feed rolls, and in contact with the seam formed by the overlapping edges of the paper web, or closely adjacent thereto in heat relation therewith, and hence its periphery moves with a tangential component of motion in the plane of the seam of the overlapping edges of the paper web. The relations between the diameters of feed roll 5 and disc 20 and their respective driving sprockets 1 and I! may be so designed that disc 2|] is driven with a peripheral speed substantially the same as the surface speed of movement of paper web 30 past disc 20 in contact therewith. However, I have found that better results. are obtained if the ratios of these respective diameters are so designed that disc 20 is driven with a peripheral speed at its area of contact with the paper web a little slower than the speed of movement of the paper web past the sealing disc 20.

As shown more particularly in Fig. 4, the metal disc 20 is provided on one of its fiat sides witha wide annular recess adapted to receive a heating element 33 which as shown, is preferably spiral in form. A circular plate member 46 fits over and closes the annular aperture in disc 20 and retains heating element 33 therein. The terminals of heating element 33 lead to binding posts 34 which are connected by leads 35 which pass to the axis of shaft I1 and axially of axis I! through an axial bore 43 formed therein, to slip rings 35 and 31 carried on shaft l1 electrically insulated therefrom by insulating material 41. The electrical heating element 33 is mounted in heat exchange relation with disc 20, and when suitable electrical energy is applied to terminals 34 through its connections, the disc 20 becomes heated.

Carried upon bearing bracket I3 is a brush bracket 44 affixed thereto by screws 45. Brush bracket 44 carries brush members 38 and 39 which are respectively adapted to engage slip rings 36 and 31. Brushes 38 and 39 are connected to a suitable source of electrical energy by wires 40 and ll. Cover plate 46 is attached to disc 20 by screws 50 which are easily removable, thereby permitting the easy removal of electrical heating element 33 from disc 20, as shown in Fig. 7. Cover plate 46 is provided with a central aperture 43, as shown in Fig. 7.

The size, construction, and heating element of the disc 20, are such that when the web of coated paper passes through the machine, heat will be supplied to the seams or edges of the paper to be connected together, at the proper temperature and for the proper length of time, in order that the wax or other treating substance applied to the paper, will first be melted, and the adhesive which in ordinary operation has been applied to the paper, will be permitted to flow into contact with the paper, and the cells or pores of the paper will be caused to expand and to permit the adhesive to be more freely absorbed by the fibres of the paper. While in ordinary practice, a suitable adhesive will have been applied to the formed edges of the paper web before reaching the sealing disc, there are some types of such treated papers for which it is not necessary to apply an adhesive, since the melted treating compound itself applies after hardening sufiicient adhesion to constitute a good seal. When the adhesive is used, the application of heat from the sealing disc causes the adhesive to set more quickly, and when the heat is withdrawn, the wax or other treating substance so melted will be permitted to congeal about the same or edges of the paper so sealed together, whereby a moisture proof seal about the connection of the edges of the paper will be established. By providing the type of structure which has -been described, in which the moving disc makes only a brief contact with a given point on the travelling web, practically no resistance is offered to the movement of the travelling web, thereby accelerating the rate of production.

It will be understood that my improved sealing device, which is supported forwardly of the feed rolls, may be easily removed from the bag machine when it is desired to make bags from ordinary papers which have not been treated with adhesive repellent compounds.

In operation, the separate portions 3. and 32 of the waxed or similarly treated paper from which bags are to be made, are formed by folding over mechanisms well known in the art provided in usual bag making machines to form the web or bag tubing 30, from which the blanks to constitute individual bags are out. There is a seam where the edges 3| and 32 overlap after being formed into web 30. As the formed web is drawn through the bite of feed rolls 5 and B by the action thereof, the heated sealing disc 20 applies heat to the overlapping edges and causes adhesion of the edges, as has been explained. The sealing disc 20 is cooperatively driven with feed roll 5 at a speed such that the peripheral speed of disc 20 at its area of contact with web 30 is substantially the same as the surface speed of web 30 past disc 20, or slightly less than said surface speed of the web, as has been explained. It will also be understood that in normal operation, a suitable adhesive will have been applied to the respective overlapping edges while separate and before being formed into the web.

' Upon leaving the heated sealing disc 20, the travelling web 30 will enter between the feed rolls 5 and 6 and be pressed thereby, causing the overlapping edges of the web to become firmly adherent, thus resulting in a strong seam. The electrical heater element 33 will maintain sealing disc 20 at the proper temperature for effectively applying heat to the seam, and because of the adjustable feature of the device, the position of the sealing disc 23 may be varied and adjusted to the point where it will be most effective.

Because of the fact that the sealing disc 20 is cooperatively driven with the feeding mechanism of the feed rolls, there is no interference between the operation of one with that of the other, and it is therefore not necessary to reduce or adjust the speed of the machine when the sealing disc 20 is employed, and since disc '20 is bodily displaceable with feed roll 5, the possibility of distorting or injuring the paper .web when traversing that section of the machine, is'obviated.

It is to be noted that when varying the length of the stub shaft I1 carrying the disc 20, said disc may be set at the proper position over the bed I of the machine to adequately contact with the overlapping edges of the travelling. web.

I claim:

1. In a machine for making bags from a web having overlapping edges and traversing said machine, a web-feeding mechanism, a heat-conducting disc member rotatably mounted in said machine and disposed to contact peripherally with the overlapping'edges of said web, electrical heating means comprised in said disc member for applying heat to said disc member for sealing said web, and means cooperatively actuated with said web-feeding mechanism for rotating said disc member in the same direction as the movement of said web at the area of contact therewith at a peripheral speed of its web-engaging surface slightly less than the speed of movement of said web at said area of contact.

2. In a machine for making bags from a web having overlapping edges and movable in said machine, a web-feeding mechanism, a support, a shaft rotatable in said support, a heat-conducting disc member carried by and rotatable with said shaft and disposed to contact peripherally with the overlapping edges of said web, an electrical heater element comprised in said disc member for applying heat to said disc member for sealing said web, electrical terminals for said heater element carried on said disc member, a pair of slip-rings rotatable with said shaft and respectively connected to said terminals, a pair of brushes carried by said support and adapted to engage said slip-rings respectively, means for supplying electrical energy to said brushes, and means for driving said shaft cooperatively with said web-feeding mechanism at a speed such that the web-engaging surface of said disc member moves at a peripheral speed slightly less than the speed of movement of said web at the area of contact therewith.

3. In a machine for making bags from a web having overlapping edges and traversing said machine, a web-feeding mechanism, a support, a shaft rotatable in said support, a heat-conducting disc member carried by said shaft and disposed to contact peripherally with the overlapping edges of said web, an electrical heater element comprised in said disc member for applying heat to said disc member for sealing said web, electrical terminals for said heater element carried on said disc member, a pair of slip-rings rotatable with said shaft and respectively connected to said terminals, a pair of brushes carried by said support and adapted to engage said slip-rings respectively, means for supplying electrical energy to said brushes, and means for driving said shaft cooperatively with said web-feeding mechanism at a speed such that the web-engaging surface of said disc member moves at a peripheral speed slightly less than the speed of movement of said web at the area of contact therewith.

4. In a machine for making bags from a web having overlapping edges and traversing said machine. a web-feeding mechanism, a heat-conducting disc member rotatably mounted in said machine and disposed to contact peripherally with the overlapping edges of said web, heating means for applying heat to said disc member for sealing said web, and means cooperatively actuated with said web-feeding mechanism for rotating said disc member in the same direction as the movement of said web at the area of contact therewith at a peripheral speed of its web-engaging surface slightly less than the speed of movement of said web at said area of contact.

5. In the manufacture of paper bags from wax coated material, the method of sealing the seam in a moving-formed bag webbing having overlapping edges, which comprises positioning and rotating a heated member in contact with said webbing while maintaining the web-engaging surface of said heated member at a temperature sufilcient to seal said overlapping edges, and moving said web-engaging surface of said heated member in the direction of movement of said webbing at a speed slightly less than the speed of movement of said bag webbing.

STUART MOORE. 

